Index - Click to read a section
The Essential Amino Acids
Branched Chain Amino Acids (BCAAs)
Free-Form Amino Acids
Food or Amiono Acids
Do Athletes and Body Builders Need More Protein (Amino Acids)?
The Costs (Health and Monetary)
Some claims and the Science (or lack thereof) Behind them
Amino acids are considered the building blocks of proteins. Breaking down protein will yield 22 known amino acids. There are three types of amino acids. These are indispensable(essential), conditionally dispensable, and dispensable. Conditionally dispensable amino acids can be synthesized from other amino acids by our bodies. Dispensable amino acids are considered non-essential. Amino acids are "one of the six basic nutrients our body needs". Essential Amino Acids acids are central to our discussion with regards to their use in weightlifting and training.
Of 22 amino acids, 8 or 9, are considered essential because our bodies
can't manufacture them. These are tryptophan, lysine, methione, phenylalaine,
threonine, valine, leucine, isoleucine, and histadine. Leucine "serves
as a substrate for muscle metabolism during periods of cellular energy
depletion" and promotes healing of the skin and broken bones as well
as improving alertness. Tryptophan, whose benefits include calming, stimulating
the release of growth hormones, and cholesterol reduction, is the only
essential amino acid whose free form is not currently available in the
U.S. lsoleucine helps in the formation of hemoglobin and is used by the
muscles for energy. Valine, which promotes muscle coordination, remains
unprocessed by the liver allowing it to go directly to muscles. Histadine
dilates blood vessels, helps to alleviate symptoms of arthritis and ulcers,
and helps in the production of red and white blood cells.
Lysine builds new body tissue and bone, enhances fertility, improves concentration, and may be an effective treatment for certain forms of herpes. Methione reduces fat and protects the kidneys and may also reduces cholesterol levels. Phenylalaine serves to reduce hunger pains, helps in the production of Norepinephrine and collagen, and improves memory and alertness. Threonine assists in metabolism and assimilation, prevents fatty build-up in the liver, and is a component of collagen.
Studies indicate that the presence of branched chain amino acids (leucine, isoleucine, and valine) after training is "critical for recovery" If they are ingested before exercise they may "alter hormonal responses to high intensity exercise". BCAA supplementation occurring during the exercise may have several health benefits, including "improved physiological and psychological responses to endurance exercise". BCAA's can compromise up to thirty-five percent of muscle tissue and a lack of any one of the three can "result in a decrease in muscle strength and tone"(Nature's Pantry Free Pamphlet). It should be noted that research on BCAA's is preliminary. Recent studies have shown "that supplementing the diet with BCAA's does not produce significant increases in lean body mass and/or muscular performance"(Phillips, 1995) "At present, there are little data to support an ergogenic effect of BCAAs using dosages that are physiologically tolerable"(Clarkson, 1996).
Free form amino acids do not require any digestion and small amounts
can easily and quickly reach our bloodstream allowing them to be used immediately
by muscles and tissues. The objective is often to trick the liver, by taking
doses that "exceed the liver's capacity, resulting in the aminos being
directed to the tissues that require them".
Technically we can "obtain essential amino acids by consuming plant
or animal food". Intact protein, the kind that can be gained from
everyday meals, is "actually absorbed more readily than free form
amino acids". Studies have found that nitrogen retention is poorest
when using amino acid supplements instead of food.
http://www.alDhanetl.com/nutritionlvnprotn.htm (hftp://www. imp. mtu - edu/-babucher/mfwfag.txt)
Essential amino acids are more effective when consumed in proper proportions to one another. "If a single essential amino acid is not present in available in the meal, or is in low amount" our bodies may not be able to fully use the others ingested. Eating animal product foods, or a variety of vegetables which contain all of the essential amino acids, is recommended. Commercial advertisements make such claims as "even if you eat the right foods soon after training, the nutrients will arrive at the muscle too late to take full advantage of the window of opportunity". However, "if you're consuming an adequate amount of complete proteins in the diet, you don't need amino acid tablets or capsules at all (Phillips, 47).
The essential amino acid requirements were determined only for resting persons and "the recommended maximum protein requirements may not be adequate for physically active individuals". Researchers found, for example, that a two-hour ride on a cycle ergometer can burn off 90% of the current estimated leucine requirement, leading them to conclude that "a reevaluation of minimum daily requirements should be considered for physically active humans". Also, "to a greater extent during exercise, there is a significant interorgan flux, which results in redistribution of amino acids from one tissue to another". (Evans et al. 1983) Habitual endurance exercise "was associated with dietary protein needs greater than the current Recommended Dietary Allowance(RDA)"(Meredith et al, 1987) Tarnopolsky et al. also found that "protein requirements for athletes performing strength training are greater than for sedentary individuals and are above current Canadian and US recommended daily protein intake requirements for healthy young males (1995). As a general rule 0.8-1.2 grams of protein per pound of body weight are sufficient quantities for bodybuilders and other athletes although "the RDA for average daily intake of protein for adult men and women is 0.36 grams of protein per pound of body weight".
Excess amino acids and proteins can have detrimental effects on the human body. "Excessive protein intake can damage the kidneys, cause dehydration and electrolyte losses, and increase calcium losses." (http://www.alphanet1.com/nutrition/vnprotn.htm)
Amino acid supplements, no matter what form they take, are quite expensive.
Depending on the amino acid, capsules or powders can run anywhere between
four and sixty dollars. When we multiply these costs by all of the different
amino acids that are recommended by companies, it is not inconceivable
for one to spend hundreds, if not thousands, of dollars on items whose
validity is not even scientifically solidified. (http://haven.ios.com/~nutripro/now/n_amino.html)
Some Claims and The Science (or lack thereof) Behind Them
A multitude of advertisements in magazines and on the worldwide web
indicate that taking amino acids will "make you a healthier and more
There are mistruths, perhaps due to pure ignorance, regarding the contents of products and their benefits. For example, Powershack's Amino Acid 2200B claims to contain all ten essential amino acids including "peptide bonds with free form amino acids", yet the free form of tryptophan is currently unavailable in the United States and can only be gained from natural food sources.
"Amino acids are commonly ingested as ergogenic acids in the belief that they enhance protein synthesis and stimulate growth hormone release" but in a study of seven male bodybuilders the ingestion of amino acid supplements in the quantities recommended by the manufacturer produced no effect.(Lambert et al., 1993)
In theory, the greater the amount of BCAA's in the bloodstream, the lower the fatigue of an individual. However, "ingesting the amounts of BCAA's necessary to exert such an effect is likely to result in gastrointestinal disturbances and slow water transport across the gut, both being disadvantageous to exercise".(Clarkson, 1996)
Bill Phillips, the editor of Muscle Media 2000 claims, "I don't
know many bodybuilders that still use amino acid tablets or capsules as
a source of protein-in my opinion it's just not necessary". Phillips
continues, calling amino acid supplements "just about worthiess"(47).
The scientific research to support the claims made by manufacturers of
amino acid supplements is lacking and/or incorrect. Before going out and
spending hundreds of dollars on such supplements, be aware that they may
have no effect. Even if they do have an effect, it is likely to be a minimal
one, perhaps no more of an advantage than the nutrients one can gain from
a well-balanced meal. One thing is clear though. Bodybuilders, and those
participating in heavy training or exercise, may need higher protein intake
than sedentary persons.
Clarkson, Pricilia M. Nutrition for Improved Sports Performance,
Sports Medicine, 1996 (6) 393-401
Evans, William J. & E.C. Fisher, R.A. Hoerr, and V. R. Young, Protein Metabolism and Endurance Exercise, The Physician and Sports Medicine, 1983, 11(7) 63-71
Lambert, Ml- Hefer, JA, Millar RP MacFarlane PW, Failure of Commercial
Oral Amino Acid Supplements to Increase Serum Growth Hormone Concentrations
in Male Body-Builders, International Journal Of Sports Nutrition,
1993, 3(3) 298-305
Meredith, C.N., & M.J. Zackin, W.R. Frontera, and W.J. Evans, Dietary
protein requirements and body protein metabolism in endurance-trained
men, Journal of Applied Physiology, 1989, 66(6) 2850-2856
Phillips,Bill, Supplement Review 1996, Mile High Publishing Inc.,
Tarnopoisky, Mark A. & J. Duncan MacDougall, and Stephanie Atkinson,
Influence of Protein Intake and Training Status on Nitrogen Balance
and Lean Body Mass, Journal Of Applied Physiology, 1988, 64(l)
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